package bike.snu.ac.kr.job.subgroup;

import java.io.IOException;
import java.util.Iterator;

import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.Reducer.Context;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.TextInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.lib.output.TextOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.bikelab.se3.rdf.reader.NoLineToParseException;
import org.bikelab.se3.rdf.reader.RdfReaderFactory;
import org.bikelab.se3.rdf.reader.WrongNumberOfSegmentsException;
import org.semanticweb.yars.nx.Node;



public class SubPropertyFilter extends Configured implements Tool {

	private static int iteration_count = 0;
	private static int iter;

	public static class Map extends Mapper<LongWritable, Text, Text, Text> {

		private Text word_key = new Text();
		private Text word_value = new Text();

		// Map function for first iteration
		public void map(LongWritable key, Text value, Context context)
				throws IOException, InterruptedException {

			String line = value.toString().trim();
			
			try {
				Node[] quad = RdfReaderFactory.parseNqLine(line);
				String s=quad[0].toN3();
				String p=quad[1].toN3();
				String o=quad[2].toN3();
				if(p.contains("<http://www.w3.org/2000/01/rdf-schema#subPropertyOf>")){
					
					word_key.set(p);
					word_value.set(value);//<0> represent outlinks
					
					context.write(word_key, word_value);
				}
				
				
			} catch (WrongNumberOfSegmentsException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (NoLineToParseException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
			

		}
	}

	public static class Reduce extends Reducer<Text, Text, Text, Text> {

		public void reduce(Text key, Iterable<Text> values, Context context)
				throws IOException, InterruptedException {
			Text newkey = new Text();
			Text newvalue = new Text();

			Iterator itr = values.iterator();
			while (itr.hasNext()) {
				String value = itr.next().toString().trim();

				newkey.set(value.toString());
				newvalue.set("");
				context.write(newkey, newvalue);
			}

		}

	}

	@Override
	public int run(String[] args) throws Exception {

		// String input =args[0];
		//
		// String output=args[1];

		Job job = new Job(getConf());
		job.setJarByClass(SubPropertyFilter.class);
		job.setJobName("sub-property filter");

		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(Text.class);

		job.setMapperClass(Map.class);
		job.setReducerClass(Reduce.class);

		job.setInputFormatClass(TextInputFormat.class);
		job.setOutputFormatClass(TextOutputFormat.class);

		FileInputFormat.setInputPaths(job, new Path(args[0]));
		FileOutputFormat.setOutputPath(job, new Path(args[1]));

		boolean success = job.waitForCompletion(true);

		return success ? 0 : 1;

	}

	public static void main(String[] args) throws Exception {
		int ret = ToolRunner.run(new SubPropertyFilter(), args);
		System.exit(ret);

	}
}
